Telephone system



Aug. '11, 1931. H. B. JOHNSON ET AL TELEPHONE SYSTEM Filed Sept isiaeea HERBERT B. JOHNSON, 035 FLUSHING, NEW YORK, AND EBICH VON NOSTITZ, OF WEST- FIELD, NEX/V JERSEY; SAID JOHNSON ASSIGNOR TO BELL TELEPHONE LABOBA- TOEIES, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK, AND SAID VON NOSTITZ ASSIGNOR TO AIVIERICAN TELEPHONE AND TELEGRAPH COM- PANY, A CORPORATION OF NEVJ YORK I TELEPHONE SY$TEM Application filed September 11, 1930.

This invention relates to telephone systems and particularly to special service trunks.

Modern telephone practice demands the utmost speed in completing connections and consequently in large systems where a great number of telephone numbers are constantly being changed the work of the intercepting operators is important and they should be given equipment to handle tratlic with the least delay possible and the least annoyance,

to the calling subscriber. The present invention comprises an intercepting operators trunk and cord circuit whereby calls to changed numbers may be completed by the intercepting operator without a demand by her that the calling subscriber make a new call and whereby supervision is given to the originating operator who handled the call in the first instance.

In accordance with one feature of this invention means are provided whereby an established telephone connection will comprise a source of talking current and a supervisory device at the out oing end of a trunk a holding device at the incoming end ofthe trunk responsive to the said talking current, a break point in the circuit beyond the holding device, a bridge for operating the said supervisory device beyond the said break point, and means under control of a called subscriber for operating the break point. Thus where such a connection involves least the calling subscriber, the originating operator, the intercepting operator and the called subscriber the supervisory signals will be operated before the originating operator without calling in the intercepting operator until the connection is to be taken down.

Another operating feature in this special service is the necessity for the intercepting operator to communicate with the originat ing operator to the exclusion of the calling subscriber for in some instances it is more expedient for the originating operator to reroute the call than it is for the intercepting operator to forward such call. Accordingly, each intercepting operators trunk has companion to it a talking circuit terminat- Serial No. 481,158.

ing in a companion outlet at the incoming end and arranged to be connected to the originating operators head set through the operation of the trunk terminals at the outgoing end.

The drawings are two figures on a single sheet. Fig. l is a diagram of the circuit arrangement showing an intercepting operators trunk leading from a completing operators position to an intercepting operators position together with the intercepting operators cord circuit. Fig. 2 is a schematic showing the essentials of one feature of this invention.

The portion to the left of the broken line of Fig. 1 represents the circuits and equipment found at a completing operators position. The intercepting trunk terminates in a jack 1 having tip and ring contacts 2 and 3 connected to trunk conductors 4i and 5, re spectively. Companion to this trunk circuit is a talking circuit comprising conductors 6 and 7 which terminate in extra contacts 8 and 9, respectively. When a plug is inserted in jack 1 then the contacts 8 and 9. are moved into connection with contacts 10 and 11 respectively so that the talking circuit comprising conductors 6 and 7 is connected to the operators telephone set.

This outgoing truck jack may be placed at a number of different kinds of completing operators positions but in any case the circuit connected to it will place ground and battery on the tip and ring. This is shown schematically in Fig. 2 where ground and battery through the repeating coil windings 12- and 13 and the supervisory device 14 are shown connected to the conductors l and 5. T 1e current supplied by this source of battery operates the relay 15 connected across the trunk and this relay in pulling up its armature completes a circuit from ground, armature and front contact of relay l5, winding of relay 16, inner left hand armature and back contact of relay l7, inner left hand armature and back contact of relay 18, back contact and inner right hand armature of relay 19 to battery. Relay 16 becomes energized in this circuitand establishes a new circuit from ground front con- 'batter Rela 18 becomes ener ized tact and armature of relay 16 winding of relay 16, back contact and right hand armature of relay 19 to battery. Relay 17 becomes energized and locks in a circuit from ground. armature and front contact of res lay l5 innermost right armature and front contact of relay 1'? and thence to. battery over the circuit traced. Upon the energization of relay 17 the circuit of relay 16 is opened and this relay after an appropriate interval releases its armature to normal. Thereupon a circuit is established from ground, normal contacts of relay 16, front contact and middle right hand armature of relay 1?, winding of relay 18 to and locks to the front contact of relay 15.

Relay 18 now closes a circuit from ground at its outer right hand armature and front contact, the front contact and outer left hand armature of relay 17 calling signal 20 to battery. Signal 20 operates and indicates to the operator that a call is awaiting attention on the trunk terminating in jacks 21 and 22. At the same time a circuit is established from source of ringing current 23, condenser 21, front contact and outermost right hand armature of relay 17 to ring conductor 5 and this source of ringing tone transmits to the calling subscriber the characteristic ringing signal so that the calling subscriber will be appraised of the fact that the call has been forwarded.

The intercepting operator now inserts plug 25 into jack 21 to answer the call. This will primarily result in a circuit from battery, supervisory lamp 2G, resistance 27, left hand armature and back contact of relay 28, sleeve of plug 25, sleeve of jack 21, right hand low resistance and left hand high resistance windings of relay 19- in series to ground. 'telay 19 becomes energized in this circuit and opens the energizing circuit of rel: i 17. Relay 1T deenergizes and returns 1 s armaturcs LO normal. The original energizing circuit of relay 18 is now opened but this relay remains locked to. the front contact of relay 15.

A talking circuit may now be traced from tip of jack 1. jack spring 2, conductor 1, outermost left hand armature and front contact of relay 1, resistance 29 and condenser 30 in parallel therewith, the ring contact of jack 21, ring of plug 25, supervisory relay 31, repeat-ing coil windings 32 and tip of plug 25, tip of jack 21, condenser 3 1, back contact and outermost right rand armature of relay 17, ring conductor 5, jack spring Thus, although ground and battery are connected to conductors 1- and 5 and still maintain relay 15 energized, no direct current path will be found through the repeating coil windings 32 and 33 on account of the condenser 34. Therefore, any supervisory device, such as 14,

which may be connected in circuit with conductor 5, will fail to operate at this time.

lVhen the operator through the use of listening key 35 communicates with the calling subscriber and finds out that through the facilities at her command she may complete the intercepted call, she inserts the plug 36 into an ap n'opriate jack. When the called subscriber answers the supervisory relay 37 will operate. This will connect battery to the winding of relay 28 which in turn will bring up its armatures. The left hand armature will open the circuit of relay 19 and this relay now becoming deenergized connects a resistance 38 about condenser so that current from the source of talking current connected to jack 1 will now flow through the windings 32 and and cause the supervisory device thereat to operate.

lVhen the called subscriber answers and causes the operation of relay 37 relay 28 in bringing up its right hand armature shunts the calling supervisory lamp 339 and causes it to grow dark in the usual manner. At the same time supervisory lamp 26 is caused to be dark since its energizing circuit is At the end of the conversation when the called subscriber connected through plug 36 hangs up and can. es the deenergization of relay 37 then relay 19 will again be operated to open the shunt about condense 3 1 and thus cause the distant supervisory device to operate. The supervisory device 39 will also operate to indicate that the-called subscriber has hung up. Although the sleeve circuit has now been closed by the deenergization of relay 28 to cause the cnergization of relay 19 supervisory lamp 26 will not operate as yet since high resistance Winding of relay 19 allows insullicient current to flow through such signal lamp 26. The action of relay 19 in placing the condenser in series with the bridge consisting of repeating coil. windings and while deenergizing the distant supervisory device 11 also deenergizes the supervisory relay 31. hen the originating operator takes the plug out of jack 1 then the holding relay 15 will become deenergized and moving its armature to its bacl: contact will short circuit the high resistancev winding of relay 19 so that supervisory lamp 26 now receives enough current to glow. This is signal. to the intercepting operator that the cord circuit may now be taken down.

If in answer to the calling subscribers request the intercepting operator finds that the connection may be more easily handled by the originating operator she inserts plug 25 into jack 22 and thereby puts herself into immediate communication with the originating operator.

The schematic circuit representation in Fig. 2 shows how an established connection will involve a source of talking current and a supervisory device connected to a trunk having a relay responsive to this source of talking current, a break point in the trunk beyond the holding relay, a bridge across the trunk beyond the said break point, a source of talking current inductively coupled with the trunk and a supervisory device for controlling the said break point. In the schematic drawing relay 37 is shown with a back contact since it actually controls a relay 28 having a back contact. Through an arrangement of this sort the supervisory signals initiated by the called subscriber are relayed past the intercepting operator to the originating operator without elfecting the intercepting trunk which is held by relay 15.

What is claimed is:

1. An established telephone connection, comprising a source of talking current and a supervisory device, a trunk circuit including a holding relay responsively to said source of talking current, a break point in said trunk beyond said holding relay, a bridge circuit across said trunk beyond said break point, another source of talking current and a supervisory device inductively coupled with said bridge circuit, and means controlled by said second supervisory device for controlling said break point for in turn controlling said first supervisory device.

2. An established telephone connection, comprising a source of talking current and a supervisory device, a trunk circuit including a holding relay responsive to said source of talking current, a break point in said trunk beyond said holding relay, a bridge circuit across said trunk beyond said break point, another source of talking current and a supervisory device inductively coupled with said trunk circuit, and means including said second supervisory device and a separate conductor for controlling said break point.

3. In a telephone system, an operators position including an operators telephone set, a trunk outgoing from said position, a circuit companion to said trunk, and means responsive to a connection to said trunk at said operators position to connect said companion circuit to said operators telephone set.

l. In a telephone system, an operators position including an operators telephone set, a trunk outgoing from said position, connection terminals for said trunk at said position, a circuit companion to said trunk, and means responsive to the actuation of said connection terminals for connecting said companion circuit to said operators telephone set.

5. In a telephone system, an operators position including an operators telephone set, a trunk jack accessible at said position, a trunk outgoing from said position terminating in said jack, a talking circuit, contacts on said jack for connecting said talk ing circuit to said telephone set, and a pair of companion jacks at the distant end of said trunk in which said trunk and said talking circuit terminate.

6. In a telephone system, a first operators position, a second operators position, a trunk between said positions, connection terminals for said trunk at said positions, a talking circuit companion to said trunk terminating in separate connection terminals at said second operators position, and means responsive to the operation of said trunk connection terminals at said first oper ators position for extending said talking circuit.

7. In a telephone system, a first operators position, an operators set thereat, a second operators position, a trunk between said positions, connection terminals for said trunk at said positions, a talking circuit companion to said trunk terminating in like connection terminals at said second operators position, and means responsive to the operation of said trunk connection terminals at said first operators position for connecting said talking circuit to said operators set.

8. In a telephone system, a first operators position, a second operators position, trunks between said positions, connection terminals for said trunks at said positions, a talking circuit individual to each said trunk between said positions, connection terminals for said talking circuits at said second position contiguous to the connection terminals of said associated trunks, and means responsive to the operation of said trunk connection terminals at said first position for extending said talking circuits.

9. In a telephone system, a first operators position, an operators telephone set thereat, a second operators position, trunks between said positions, said trunks terminating in jacks at said positions, a talking circuit individual to each said trunk between said positions, said talking circuits terminating in jacks at said second operators position and in jack contacts of the respective corresponding trunk jacks in said first operators position, and other jack contacts cooperating with said talking circuit jack contacts to extend said talking circuits to said operators telephone set.

In witness whereof, we hereunto subscribe our names this 13th day of August, 1930.

HERBERT B. JOHNSON. ERICH VON NOSTITZ. 

